Ossification of the posterior longitudinal ligament of the cervical spine.

Although ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is an uncommon condition, its strong prevalence among the Japanese and non-Japanese Asians is well known. Genetic predisposition coupled with ageing and an imbalance in bone-seeking hormones are some actiological factors postulated in recent years. Imaging is directed at showing the calcified mass, cord compression and any attendant damage, as the latter are important prognostic factors. We describe 6 cases of OPLL of the cervical spine seen at Westmead Hospital between 1979 and 1994. Of the 4 patients presenting with disabling compressive myelopathy, 3 made significant recovery following surgical decompression. Characteristic plain film features manifesting as a dense calcified linear structure along the course of the posterior longitudinal ligament (PLL) were present in 5 patients, including 1 who was asymptomatic. Computed tomography (CT) was invaluable in demonstrating the full extent of the disease in all 5 symptomatic patients. Magnetic resonance imaging (MRI) was helpful in excluding myelomalacia in 2 patients prior to successful surgery. The myelopathy caused by cervical OPLL remains rare, affecting mainly middle aged males of Asiatic and European extraction.

Spontaneous bone graft resorption in os odontoideum.

Two children are presented who had posterior fusion of the upper cervical spine for os odontoideum. Both patients achieved radiographic fusion but spontaneous bone graft resorption occurred, resulting in a recurrence of the original instability. An awareness of this phenomenon, which has been rarely reported, is important in the pre-operative counselling and postoperative follow-up of these patients.

Harrington instrumentation without fusion plus external orthotic support for the treatment of difficult curvature problems in young children.

In selected patients a method of rod insertion without fusion combined with use of a full-time external orthotic support, e.g., the Milwaukee brace, is effective. The orthopedic surgeon confronted with young children who have curves that do not respond to conservative treatment alone or in which bracing is contraindicated should find this procedure particularly suitable. The method allows for the expression of full growth potential while maintaining curve correction.

The role of bone scans in the assessment of prognosis of scaphoid fractures.

Fifty patients with radiographic evidence of an acute scaphoid fracture were studied prospectively. Technetium bone scans were performed on all patients soon after injury in an attempt to detect fractures at risk of non-union or avascular necrosis. In three patients the scan showed a focal area of decreased radionuclide concentration in the region of the proximal pole of scaphoid implying avascularity, and each developed the radiographic signs of avascular necrosis. Two of these patients, each with a displaced fracture, developed non-union. Acute fractures of the scaphoid with evidence of avascularity on bone scan are at high risk of developing non-union.

Reconstructive surgery in the adult for failed scoliosis fusion.

Fifty-nine adult patients were examined who had undergone previous spine surgery for scoliosis but in whom pain (78 per cent), loss of correction (68 per cent), or dyspnea (36 per cent) subsequently developed. Twenty-six patients had idiopathic scoliosis, twenty-five had paralytic scoliosis secondary to poliomyelitis, and eight had scoliosis secondary to miscellaneous etiologies. A one-stage reconstructive procedure was performed in sixteen patients and a two-stage procedure, in forty-three patients. The two-stage procedure consisted of exposure of the spine and multiple osteotomies, followed by two weeks of halofemoral traction to obtain correction. The spine fusion was then extended, using Harrington instrumentation to maintain correction. At an average follow-up of 3.3 years there was reduction of pain in 67 per cent of the patients and a solid fusion in all but two. The complication rate was high (71 per cent), the most important complications being pseudarthrosis, wound infection, urinary tract infections, loss of lumbar lordosis, and pressure sores. The mortality rate was 3.4 per cent. No patient became paraplegic at the initial surgical procedure and early recognition and treatment of pseudarthrosis will reduce the number of patients requiring this salvage operation.